The invention relates to a linear guidance unit, comprising an elongated guide housing with a longitudinal axis and with, defining a guide cavity, walls, namely a bottom wall and two side walls, the two side walls forming between them, opposite the bottom wall, a longitudinal opening in the guide cavity, and further comprising an axially parallel guide rail mounted inside the guide cavity and on at least one of these walls, a traveller guided to roll on this guide rail and secured against tilting about the longitudinal axis, the said traveller being adapted to be connected through the longitudinal opening to a first connection member, and further comprising a linear drive for propelling the traveller in the direction of the longitudinal axis.